1. Field of the Invention
The present invention relates to multiple-blade saw systems with saw guide lubricating systems and, more particularly, to a multiple-blade saw system having a magnetic bearing guide surface and a ferromagnetic lubricant, coolant and coating fluid which allows for continuous regeneration of the saw bearing guide surface with ferromagnetic particles.
2. General Background
Multiple blade saw systems used in the lumber industry use very thin circular saw blades which tend to warp and deform during use. Therefore, mechanisms have been deployed to prevent warping and deformation of the blades. It is common for guiding systems to use large babbitt saw guide blocks which typically require large amounts of cooling water to cool both the saw blades and saw guide blocks while the saws are cutting.
Under the current operating conditions, temperature is controlled through the introduction of cooling fluids to the blade and guide interface. However, the current systems, operating under current conditions, do not generate enough heat to allow extreme pressure lubricant additives such as chlorine or sulfur to effectively minimize the effects of blade and bearing guide impacts through low surface friction metal salt formation. Furthermore, any metal salt formation on the surface of the bearing guide is dependent on the surface height of the remaining metal, which will precipitously decrease as wear occurs and does not effectively address the problem.
In addition, the impacts that do occur degrade the ability of the guide block to keep the axially opposed saw blades on plane and cutting properly. As impact wear occurs on the bearing guide leading edge, trailing edge and additional load points, the ability of the bearing guide to keep the blade spinning on its original plane, especially during impact conditions, is precipitously decreased.
Another attempt at preventing excess accumulation of heat in multiple saw assemblies, with little or no water, is described in U.S. Pat. No. 4,635,513 (incorporated herein by reference as if set forth in full below). In this system a plurality of individual saw guide blocks are provided, each of which include separate channels to deliver water and oil mists to the saw blade. The application of small amounts of lubricating oil to the saw blade reduced the amount of water to cool the blades. The introduction of oil and water mists increased the service life of the saw guides, typically to 100 hours or longer.
The introduction of oil and water mists onto the saw guides is also disclosed in U.S. Pat. No. 4,848,200 (incorporated herein by reference as if set forth in full below). This system also uses a low friction material on the bearing surface to reduce heat generation as the blades are rotated (FIGS. 1 and 2). The combination of oil and water mists and the low friction material has significantly increased the service life of the saw guides, typically to 5,000 to 10,000 hours.
In view of the above, there is a continuing need for a magnetic saw bearing guide surface and ferromagnetic lubricant, coolant and coating fluid for use with multiple-blade saw systems to reduces frequent changes of the guide blocks due to the effects of metal to metal contact as saw blade and bearing surface impact.
For the above reasons, it would be desirable to provide a magnetic bearing guide surface and ferromagnetic lubricant, coolant and coating fluid that will continually regenerate the bearing guide surface to extended the useful life thereof in order to reduce costs associated with frequent changes.
As will be seen more fully below, the present invention is substantially different in structure, methodology and approach from that of prior saw guide lubricating systems.